NFS Performance Tuning for HP-UX 11.0 and 11i Systems

nfs performance tuning for hp-ux 11.0 and 11i systems page 118
Notes:
Page 118July 22, 2002
Copyright 2002 Hewlett- Packard Company
Kernel Parameter Recommendations
(part 3)
kernel
parameter
tuning
Variable Description Def Recommend
25664
Max. number of kernel threads that
can be associated with a process
max_thread_proc
20481024
Specifies the “hard” limit for the
number of files that a given process
can have open at any time
maxfiles_lim
102460
Specifies the “soft” limit for the
number of files that a given process
can have open at any time
maxfiles
WARNING WARNING WARNING
Ø HP-UX 11.0 and 11i NFS servers stop responding to NFS/TCP requests if the
nfsktcpd process reaches the max_thread_proc limit. This defect is fixed in
the current 11.0 NFS patch and will be fixed in the 11i Summer 2001 patch.
max_thread_proc
Limits the number of threads a single process is allowed to create. This protects the system from
excessive use of system resources if a run-away process creates more threads than it should.
A defect exists in the HP-UX 11.0 and 11i NFS/TCP server code which causes the server to stop
responding to inbound requests once the nfsktcpd process reaches the maximum number of
kernel threads defined by max_thread_proc, effectively causing all NFS/TCP access to this
server to hang. This defect is fixed in the current 11.0 NFS patch. The same fix will be made
available for 11i in the Summer 2001 NFS patch.
Since TCP is the default network protocol used for NFS filesystems in 11i, it is important to make
sure that 11i servers configure max_thread_proc large enough to avoid this hang. Once the
Summer 11i NFS patch becomes available, max_thread_proc may be reduced to a lower
value.
maxfiles
Specifies the “soft” limit for the number of files a process may open at any one time without
having to call setrlimit(2) to increase the soft limit.
maxfiles_lim
Specifies the “hard” limit for the number of files a process may open at any one time.